Detections

Explore public detection logic contributed by the community across SIEM and rule languages.

896 detections

The following analytic detects the addition of a new custom domain within an Azure Active Directory (AD) tenant. It leverages Azure AD AuditLogs to identify successful "Add unverified domain" operations. This activity is significant as it may indicate an adversary attempting to establish persistence by setting up identity federation backdoors, allowing them to impersonate users and bypass authentication mechanisms. If confirmed malicious, this could enable attackers to gain unauthorized access, escalate privileges, and maintain long-term access to the Azure AD environment, posing a severe security risk.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0057
The analytic identifies AWS console login attempts by users from a new region. It leverages AWS CloudTrail events and compares current login regions against a baseline of previously seen regions for each user. This activity is significant as it may indicate unauthorized access attempts or compromised credentials. If confirmed malicious, an attacker could gain unauthorized access to AWS resources, potentially leading to data breaches, resource manipulation, or further lateral movement within the cloud environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0057
This analytic detects file transfers flagged as malware that occurred over non-standard ports (other than 80 and 443) from Cisco Secure Firewall Threat Defense logs. Adversaries may attempt to bypass protocol-based detection or use alternate ports to blend in with other traffic. This analytic identifies these non-conventional flows and surfaces potential evasion techniques. If confirmed malicious, this indicates potential malware delivery or other nefarious activity.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2057
The following analytic detects `spoolsv.exe` writing a `.dll` file, which is unusual behavior and may indicate exploitation of vulnerabilities like CVE-2021-34527 (PrintNightmare). This detection leverages Sysmon EventID 11 to monitor file creation events in the `\spool\drivers\x64\` directory. This activity is significant because `spoolsv.exe` typically does not write DLL files, and such behavior could signify an ongoing attack. If confirmed malicious, this could allow an attacker to execute arbitrary code, escalate privileges, or maintain persistence on the compromised system.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0055
The following analytic detects a suspicious registry modification aimed at disabling security audit logs by adding a specific registry entry. It leverages data from the Endpoint.Registry data model, focusing on changes to the "Control\\MiniNt" registry path. This activity is significant because it can prevent Windows from logging any events to the Security Log, effectively blinding security monitoring efforts. If confirmed malicious, this technique could allow an attacker to operate undetected, making it difficult to trace their actions and compromising the integrity of security audits.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0054
The following analytic detects the creation of a new DWORD value named "EnableAt" in the registry path "HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\Configuration". This modification enables the use of the at.exe or wmi Win32_ScheduledJob commands to add scheduled tasks on a Windows endpoint. The detection leverages registry event data from the Endpoint datamodel. This activity is significant because it may indicate that an attacker is enabling the ability to schedule tasks, potentially to execute malicious code at specific times or intervals. If confirmed malicious, this could allow persistent code execution on the system.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1053
The analytic identifies potential exploitation of Log4Shell CVE-2021-44228 by correlating multiple MITRE ATT&CK tactics detected in risk events. It leverages Splunk's risk data model to calculate the distinct count of MITRE ATT&CK tactics from Log4Shell-related detections. This activity is significant because it indicates a high probability of exploitation if two or more distinct tactics are observed. If confirmed malicious, this activity could lead to initial payload delivery, callback to a malicious server, and post-exploitation activities, potentially resulting in unauthorized access, lateral movement, and further compromise of the affected systems.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0047
The following analytic detects the disabling of Windows Defender services by monitoring registry modifications. It leverages registry event data to identify changes to specific registry paths associated with Defender services, where the 'Start' value is set to '0x00000004'. This activity is significant because disabling Defender services can indicate an attempt by an adversary to evade detection and maintain persistence on the endpoint. If confirmed malicious, this action could allow attackers to execute further malicious activities undetected, leading to potential data breaches or system compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1046
This analytic identifies security events from Microsoft Defender, focusing on Exploit Guard and Attack Surface Reduction (ASR) features. It detects Event IDs 1121, 1126, 1131, and 1133 for blocked operations, and Event IDs 1122, 1125, 1132, and 1134 for audit logs. Event ID 1129 indicates user overrides, while Event ID 5007 signals configuration changes. This detection uses a lookup to correlate ASR rule GUIDs with descriptive names. Monitoring these events is crucial for identifying unauthorized operations, potential security breaches, and policy enforcement issues. If confirmed malicious, attackers could bypass security measures, execute unauthorized actions, or alter system configurations.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0046
The analytic detects a suspicious registry modification that enables the plain text credential feature in Windows by setting the "UseLogonCredential" value to 1 in the WDigest registry path. This activity is commonly used by malware and tools like Mimikatz to dump plain text credentials, indicating a potential credential dumping attempt. If confirmed malicious, this could allow an attacker to obtain sensitive credentials, leading to further compromise and lateral movement within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1045
The following analytic detects modifications to undocumented registry keys that allow a DLL to load into lsass.exe, potentially capturing credentials. It leverages the Endpoint.Registry data model to identify changes to \CurrentControlSet\Services\NTDS\DirectoryServiceExtPt or \CurrentControlSet\Services\NTDS\LsaDbExtPt. This activity is significant as it indicates a possible attempt to inject malicious code into the Local Security Authority Subsystem Service (LSASS), which can lead to credential theft. If confirmed malicious, this could allow attackers to gain unauthorized access to sensitive information and escalate privileges within the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1045
The analytic detects the suspicious loading of DLLs by spoolsv.exe, potentially indicating PrintNightmare exploitation. It leverages Sysmon EventCode 7 to identify instances where spoolsv.exe loads multiple DLLs from the Windows System32 spool drivers x64 directory. This activity is significant as it may signify an attacker exploiting the PrintNightmare vulnerability to execute arbitrary code. If confirmed malicious, this could lead to unauthorized code execution, privilege escalation, and persistent access within the environment, posing a severe security risk.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1040
The following analytic identifies when a Windows Defender ASR rule disabled events. ASR is a feature of Windows Defender Exploit Guard that prevents actions and apps that are typically used by exploit-seeking malware to infect machines. ASR rules are applied to processes and applications. When a process or application attempts to perform an action that is blocked by an ASR rule, an event is generated. This detection searches for ASR rule disabled events that are generated when an ASR rule is disabled.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0040
The following analytic detects the use of PowerShell commands to add or set Windows Defender exclusions. It leverages EventCode 4104 to identify suspicious `Add-MpPreference` or `Set-MpPreference` commands with exclusion parameters. This activity is significant because adversaries often use it to bypass Windows Defender, allowing malicious code to execute without detection. If confirmed malicious, this behavior could enable attackers to evade antivirus defenses, maintain persistence, and execute further malicious activities undetected.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0039
The following analytic identifies a suspicious modification of the Windows registry setting for max connections per server. It detects changes to specific registry paths using data from the Endpoint.Registry datamodel. This activity is significant because altering this setting can be exploited by attackers to increase the number of concurrent connections to a remote server, potentially facilitating DDoS attacks or enabling more effective lateral movement within a compromised network. If confirmed malicious, this could lead to network disruption or further compromise of additional systems.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0039
The following analytic detects modifications in the Windows registry to disable Windows Defender generic reports. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the "DisableGenericRePorts" registry value. This activity is significant as it can prevent the transmission of error reports to Microsoft's Windows Error Reporting service, potentially hiding malicious activities. If confirmed malicious, this action could allow attackers to bypass Windows Defender detections, reducing the visibility of their activities and increasing the risk of undetected system compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0038
The following analytic detects modifications to the Windows registry that disable the Windows Defender raw write notification feature. It leverages data from the Endpoint.Registry datamodel, specifically monitoring changes to the registry path associated with Windows Defender's real-time protection settings. This activity is significant because disabling raw write notifications can allow malware, such as Azorult, to bypass Windows Defender's behavior monitoring, potentially leading to undetected malicious activities. If confirmed malicious, this could enable attackers to execute code, persist in the environment, and access sensitive information without detection.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0037
This analytic detects the execution of the 'shred' command on a Linux machine, which is used to overwrite files to make them unrecoverable. It leverages data from Linux Auditd, focusing on process names and command-line arguments. This activity is significant because the 'shred' command can be used in destructive attacks, such as those seen in the Industroyer2 malware targeting energy facilities. If confirmed malicious, this activity could lead to the permanent destruction of critical files, severely impacting system integrity and data availability.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0036
The analytic detects modifications to Windows Defender Attack Surface Reduction (ASR) registry settings. It leverages Windows Defender Operational logs, specifically EventCode 5007, to identify changes in ASR rules. This activity is significant because ASR rules are designed to block actions commonly used by malware to exploit systems. Unauthorized modifications to these settings could indicate an attempt to weaken system defenses. If confirmed malicious, this could allow an attacker to bypass security measures, leading to potential system compromise and data breaches.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0036
The analytic detects the modification of the Windows registry to disable the Windows Defender Submit Samples Consent feature. This activity is significant as it indicates an attempt to bypass or evade detection by preventing Windows Defender from submitting samples for further analysis. If confirmed malicious, this could allow an attacker to execute malicious code without being detected by Windows Defender, leading to potential system compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0035
This detection searches for Windows Defender ASR audit events. ASR is a feature of Windows Defender Exploit Guard that prevents actions and apps that are typically used by exploit-seeking malware to infect machines. ASR rules are applied to processes and applications. When a process or application attempts to perform an action that is blocked by an ASR rule, an event is generated. This detection searches for ASR audit events that are generated when a process or application attempts to perform an action that would be blocked by an ASR rule, but is allowed to proceed for auditing purposes.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0035
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